Artificial nitrogenous textile fiber



Patented Nov. 4, 1941 ARTIFICIAL NITROGENOUS TEXTILE FIBER =iuseppe Donagcmma and Piero Donagemma,

Milan, Italy,

assignors to Snia Viscosa" Societa Nazionale Industria Applicazioni Viscosa, Milan, Italy No Drawing. ripplication April 26, 1938, Serial No. 204,480. In Italy May 3', 1937 3 Claims. (onus-as) It is already known that caseins obtained with special coagulants may be dissolved in caustic soda solutions producing after special treatments a kind of viscose that may be coagulated in special baths and spun to a textile fibre which must be further treated with formaldehyde baths, etc. in order to make it solid and consistent.

As distinct therefrom, this invention relates to the production of artificial nitrogenous textile fibres by dissolving casein, for example commercial casein, in a mixture formed by a borate, preferably sodium borate water and caustic soda, producing a kind of viscose that may be spun alone, or added in percentage of to 75% to other viscoses of cellulose xanthogenate, cellulose acetate or cuprammonium cellulose.

The viscose thus formed maybe coagulated even in ordinary acid baths employed for coagulating viscoses from cellulose xanthogenate or other viscoses, by using the same machines and processes as for spinning ordinary viscose. The fibers obtained shall contain the same nitrogen percentage as natural wool ii! they are spun from casein viscose only, or nitrogen may be fixed in the fibers in quantities from 10 to 75% with respect to nitrogen fixed in wool by spinning 1. Preparation of a casein base viscose (11) About 2.500 kilograms casein, (D) About 0.600 kilogram borate of sodium, (c) About 2.500 kilograms water.

These substances are heated to about 50 C. and stirred over 20 minutes, whereupon '(a) 1.50 liters 18% soda (b) 9.00 liters water are added. The mixture is stirred during two hours cooling to a temperature between 24 and 28 0., filtered and evacuated.

is then carried out and ordinary machines used for spinning rayon and staple fiber may be employed.

Composition of viscose", about 15 to 16% casein, about 1.30 to 1.60% NaOH soda, about 4% borates prevailingly in the form of sodium borate.

Coagulating bath formed by: about 250 grams acid per litre, about 150 grams zinc sulphate per litre at the temperature of about -60 C.

2. Preparation of a viscose from casein with the addition of a cellulose :ranthogemte viscose (a) About 100 kgs. cellulose viscose containing 8.20% cellulose and 6.50% soda;

(D) About 8 kgs. ordinary casein;

(0) About 2.40 kgs. sodium borate,

((1.) About 8 liters water.

Sodium borate (kgs. 2.40) is mixed with water- (8 liters), and the mixture is heated to 55 0.; casein (kg. 8.00) is then slowly added stirring during about 20 minutes till a voluminous swelling coagulation product is obtained.

9 litres water mixed with 7 litres soda con-taining 18% NaOH are added, the mixture is stirred for further 20 minutes cooling to 25 C.

To this viscose from casein compounds 100 kgs. viscose in the form of cellulose xanthogenate are added, stirring for thirty minutes or longer until the two viscoses are thoroughly incorporated in each other, whereupon the mass is filtered as in the'case oi rayon viscose.

This viscose has before filtration a coagulation degree of 7 to 7%, the viscosity being -65.

After filtering, viscose is treated in vacuum for at least 10 hours in order to evacuate it, maintain ing a temperature not below about 20 C.

On addition to casein viscose," the cellulose must have previously undergone a ripening process for 5456 hours from the start of sulphur-ation.

After ten hours treatment in vacuum viscose obtained as above shall have a coagulation degree of 4 A to 4 and a viscosity of 32 to 36.

These data are stable for over fifteen hours.

The material can now be fed to the spinning machines and spun with the usual rayon spin- Ripening is carried out during 64 to '10 hours approximately at 22 to 24 C. Viscosity is thus fixed at 15-18 for 74 hours and longer. Spinning ning nozzles and coagulated with the same bath as commonly used for ordinary rayon and staple fibre.

The temperature and, in small proportions, also the concentration of said bath should be increased as the percentage of casein in the viscose in creases.

Y AIter spinning, no further baths, such as formaldehyde or other baths are required for fixing nitrogen and the fibre is treated further like staple fibre or rayon. It may be desulphurated, boiled in an acid bath, bleached in the ordinary manner or with hydrogen 'superoxide without the smallest loss of the nitrogen fixed and incorporated therein in the percentage determined before starting the treatment. What We claim is:

1. An artificial protein containing nitrogenous textile fibers comprising throughout its mass a 10 3. A process for the manufacture of artificial nitrogenous textile fibres, consisting in dissolving sodium borate in water at about 55 C., slowly adding casein while stirring for about 20 minutes, adding a soda solution containing about 18% NaOH, mixing for a further 20 minutes and at the same time cooling to about 25 0., adding a cellulosic viscose previously ripened for about 54 to 56 hours and mixing until the casein solution and the cellulose are fully incorporated with each other.

GIUSEPPE DONAGEMMA. PIERO DONAGEMMA. 

